STRATA反演软件简介ppt课件.ppt

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1、EARTHIMAGINGSOLUTIONS1STRATA2Dand3DPost-StackSeismicModelling,Processing&April1999Inversion2STRATAisaninteractive2Dand3Dmodellingandinversionprogramwhichtransformspost-stackseismictracestovelocityoracousticimpedancetraces.Theprogramincludesoptionsforbasicseismicprocessing,wav

2、eletextraction,logeditingandinterpretation,aswellasdifferentmethodsofperforminginversion.3OverviewofInversionPre-StackInversionTravelTimeInversion(Tomography)AmplitudeInversion(AVO)WaveFieldInversionBandlimitedInversionSparse-spikeInversionModel-basedInversionPost-StackInversi

3、onSeismicInversionMethodsAmplitudeInversion(STRATA)4Theinversionprocessistodeterminetheearthimpedancefromthegivenseismictracebasedontheconvolutionalmodelseismic=wavelet*reflectivity+noiseAssumptionsTheseismicdataarealreadystacked,migratedandnomultiples.Eachtracedependsonlyonth

4、eimpedancedirectlybelowthetracelocation.Thewaveletisconstantandnotvaryingwithtime.Thenoiseisrandom,whitenoise,uncorrelatedwiththeseismic.Thereisnocoherentnoise.Objective5Non-UniquenessProblem!非单值问题（CHJ注）Allinversionalgorithmssufferfromthenon-uniquenessproblem.Thismeansthatther

5、eismorethanonepossiblegeologicalmodelconsistentwiththeseismicdata.Inpractice,thisproblemishandledbyusinggeologicalconstraints,providedbywelllogs.6BasicConceptofSTRATASeismicDataVelocity/DensityControl(Logs)BuildModelInvertSeismic7BasicSteps(e.g.ModelBasedInversion)(1)Readseism

6、icandwelllogs.(2)Extractastatisticalwaveletfromtheseismic.Correlatelogsandextractagainthebestwaveletusingthewelllogs.(4)Buildinitialmodel.Setupverticalandlateralinterpolation.(5)Applyinversionandvalidatetheoutputimpedanceandsynthetic.(3)Pickorimporthorizons.ImportWellLogOpenSe

7、ismicProcessSeismicExtractWaveletExtractWaveletusingLogCreateSyntheticPickSeismicBuildModelInversionCorrelateLog8Step1:DataInput(1)Readseismicandwelllogs.(2)Extractastatisticalwaveletfromtheseismic.Correlatelogsandextractagainthebestwaveletusingthewelllogs.(4)Buildinitialmodel

8、.Setupverticalandlateralinterpolation.(5)Applyinversionandval